Memory device with status feedback for error correction

ABSTRACT

Methods, systems, and devices for a memory device with status feedback for error correction are described. For example, during a read operation, a memory device may perform an error correction operation on first data read from a memory array of the memory device. The error correction operation may generate second data and an indicator of a state of error corresponding to the second data. In one example, the indicator may indicate one of multiple possible states of error. In another example, the indicator may indicate a corrected error or no detectable error. The memory device may output the first or second data and the indicator of the state of error during a same burst interval. The memory device may output the data on a first channel and the indicator of the state of error on a second channel.

CROSS REFERENCE

The present application for patent is a continuation of U.S. patentapplication Ser. No. 16/898,354 by SCHAEFER et al., entitled “MEMORYDEVICE WITH STATUS FEEDBACK FOR ERROR CORRECTION,” filed Jun. 10, 2020,which claims the benefit of U.S. Provisional Patent Application No.62/862,254 by SCHAEFER et al., entitled “MEMORY DEVICE WITH STATUSFEEDBACK FOR ERROR CORRECTION,” filed Jun. 17, 2019, each of which isassigned to the assignee hereof, and each of which is expresslyincorporated by reference herein.

BACKGROUND

The following relates generally to a system that includes at least onememory device and more specifically to memory device with statusfeedback for error correction.

Memory devices are widely used to store information in variouselectronic devices such as computers, wireless communication devices,cameras, digital displays, and the like. Information is stored byprograming different states of a memory device. For example, binarydevices most often store one of two states, often denoted by a logic 1or a logic 0. In other devices, more than two states may be stored. Toaccess the stored information, a component of the device may read, orsense, at least one stored state in the memory device. To storeinformation, a component of the device may write, or program, the statein the memory device.

Various types of memory devices exist, including magnetic hard disks,random access memory (RAM), read-only memory (ROM), dynamic RAM (DRAM),synchronous dynamic RAM (SDRAM), ferroelectric RAM (FeRAM), magnetic RAM(MRAM), resistive RAM (RRAM), flash memory, phase change memory (PCM),and others. Memory devices may be volatile or non-volatile. Non-volatilememory, e.g., FeRAM, may maintain their stored logic state for extendedperiods of time even in the absence of an external power source.Volatile memory devices, e.g., DRAM, may lose their stored state whendisconnected from an external power source.

In some cases, data stored within a memory device may become corrupted.Some memory devices may be configured to internally detect and/orcorrect such data corruption or errors (e.g., data errors) and therebyrecover the data as stored before corruption. Improved techniques forreporting such detection and/or correction may be desired. Improvingmemory devices, generally, may include increasing memory cell density,increasing read/write speeds, increasing reliability, increasing dataintegrity, reducing power consumption, or reducing manufacturing costs,among other metrics.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example of a system that supports a memory devicewith status feedback for error correction in accordance with examples asdisclosed herein.

FIG. 2 illustrates an example of a memory die that supports a memorydevice with status feedback for error correction in accordance withexamples as disclosed herein.

FIG. 3 illustrates an example of a system that supports a memory devicewith status feedback for error correction in accordance with examples asdisclosed herein.

FIG. 4 illustrates an example of a timing diagram that supports a memorydevice with status feedback for error correction in accordance withexamples as disclosed herein.

FIG. 5 illustrates an example of a process flow that supports a memorydevice with status feedback for error correction in accordance withexamples as disclosed herein.

FIG. 6 shows a block diagram of a memory device that supports a memorydevice with status feedback for error correction in accordance withexamples as disclosed herein.

FIGS. 7 through 9 show flowcharts illustrating a method or methods thatsupport memory devices with status feedback for error correction inaccordance with examples as disclosed herein.

DETAILED DESCRIPTION

Memory devices may operate under various conditions as part ofelectronic apparatuses such as personal computers, wirelesscommunication devices, servers, internet-of-things (IoT) devices,electronic components of automotive vehicles, and the like. In somecases, memory devices supporting applications for certainimplementations (e.g., automotive vehicles, in some cases withautonomous or semi-autonomous driving capabilities) may be subject toincreased reliability constraints. As such, memory devices (e.g., DRAM)for some applications may be expected to operate with a reliabilitysubject to relatively higher industry standards or specifications (e.g.,higher reliability constraints).

Data stored in a memory device may in some cases become corrupted (e.g.,due to leakage, parasitic coupling, or electromagnetic interference(EMI)). Corruption of data may refer to an unintentional change in thelogic value of data as stored within the memory device and thus mayrefer to an unintended change in the logic value stored by one or morememory cells (e.g., from a logic one (1) to a logic zero (0), or viceversa). For example, a memory device may perform a read operation todetermine the logic value of data stored within the memory device andone or more of the memory cells may have become corrupted. A deviationin the stored logic value of a bit from its original and intended logicvalue may be referred as an error, a bit error, or a data error and mayresult from corruption. Some memory devices may be configured tointernally detect and in at least some cases correct (repair) such datacorruption or errors and thereby recover the data as stored beforecorruption. Such error detection and correction may rely upon one ormore error-correcting codes (ECCs) (e.g., block codes, convolutionalcodes, Hamming codes, low-density parity-check codes, turbo codes, polarcodes), and related processes, operations, and techniques thus may bereferred as ECC processes, ECC operations, ECC techniques, or in somecases as simply ECC. Error detection and correction conducted internallywithin a memory device on data stored previously at the memory devicemay generally be referred to as in-line ECC (whether within a single-diememory device or a multi-die memory device), and memory devices thatsupport on-die ECC may be referred to as ECC memory.

During the execution of a read operation, a memory device with ECCmemory may perform an error correction operation on data read from amemory array according to the read operation. The error correctionoperation may generate corrected data and/or an indication of a detectederror. The memory device may output data (e.g., the corrected data orthe data read from the memory array) to a host device. It may bedesirable to further output an indication of a status of the errorcorrection operation. For example, it may be desirable to indicate tothe host device whether the data is corrected or if an error is detectedwithin the data. Indicating to the host device the status of the errorcorrection operations may enable the host device to detect and addressproblematic data (e.g., data received from the memory device with astatus indicating a detected error). This may increase the reliabilityof the memory device.

Techniques for a memory device with status feedback for error correctionare described. The memory device may output the data (e.g., thecorrected data or the data read from the memory array) and acorresponding indicator of the state of error during or concatenatedwith a same burst interval. The indicator of the state of error mayindicate a status of the error correction operation. In one example, theindicator of the state of error may indicate one of three or morepossible states of error. In another example, the indicator of the stateof error may indicate that the error correction operation corrected anerror or did not detect an error. The memory device may output theindicator of the state of error on a channel that is distinct fromchannels for the data.

Features of the disclosure are initially described in the context of amemory system and memory die as described with reference to FIGS. 1-3 .Features of the disclosure are described in the context of a processflow as described with reference to FIG. 5 . These and other features ofthe disclosure are further illustrated by and described with referenceto an apparatus diagram and flowcharts that relate to memory device withstatus feedback for error correction as described with references toFIGS. 6-9 .

FIG. 1 illustrates an example of a system 100 that utilizes one or morememory devices in accordance with examples as disclosed herein. Thesystem 100 may include an external memory controller 105, a memorydevice 110, and a set of channels 115 coupling the external memorycontroller 105 with the memory device 110. The system 100 may includeone or more memory devices, but for ease of description the one or morememory devices may be described as a single memory device 110.

The system 100 may include aspects of an electronic device, such as acomputing device, a mobile computing device, a wireless device, or agraphics processing device. The system 100 may be an example of aportable electronic device. The system 100 may be an example of acomputer, a laptop computer, a tablet computer, a smartphone, a cellularphone, a wearable device, an internet-connected device, or the like. Thememory device 110 may be a component of the system configured to storedata for one or more other components of the system 100. In someexamples, the system 100 is configured for bi-directional wirelesscommunication with other systems or devices using a base station oraccess point. In some examples, the system 100 is capable ofmachine-type communication (MTC), machine-to-machine (M2M)communication, or device-to-device (D2D) communication.

At least portions of the system 100 may be examples of a host device.Such a host device may be an example of a device that uses memory toexecute processes such as a computing device, a mobile computing device,a wireless device, a graphics processing device, a computer, a laptopcomputer, a tablet computer, a smartphone, a cellular phone, a wearabledevice, an internet-connected device, some other stationary or portableelectronic device, or the like. In some cases, the host device may referto the hardware, firmware, software, or a combination thereof thatimplements the functions of the external memory controller 105. In somecases, the external memory controller 105 may be referred to as a hostor host device. In some examples, system 100 is a graphics card.

In some cases, a memory device 110 may be an independent device orcomponent that is configured to be in communication with othercomponents of the system 100 and provide physical memory addresses/spaceto potentially be used or referenced by the system 100. In someexamples, a memory device 110 may be configurable to work with at leastone or a set of different types of systems 100. Signaling between thecomponents of the system 100 and the memory device 110 may be operableto support modulation schemes to modulate the signals, different pindesigns for communicating the signals, distinct packaging of the system100 and the memory device 110, clock signaling and synchronizationbetween the system 100 and the memory device 110, timing conventions,and/or other factors.

The memory device 110 may be configured to store data for the componentsof the system 100. In some cases, the memory device 110 may act as aslave-type device to the system 100 (e.g., responding to and executingcommands provided by the system 100 through the external memorycontroller 105). Such commands may include an access command for anaccess operation, such as a write command for a write operation, a readcommand for a read operation, a refresh command for a refresh operation,or other commands. The memory device 110 may include two or more memorydice 160 (e.g., memory chips) to support a desired or specified capacityfor data storage. The memory device 110 including two or more memorydice may be referred to as a multi-die memory or package (also referredto as multi-chip memory or package).

The system 100 may further include a processor 120, a basic input/outputsystem (BIOS) component 125, one or more peripheral components 130, andan input/output (I/O) controller 135. The components of system 100 maybe in electronic communication with one another using a bus 140.

The processor 120 may be configured to control at least portions of thesystem 100. The processor 120 may be a general-purpose processor, adigital signal processor (DSP), an application-specific integratedcircuit (ASIC), a field-programmable gate array (FPGA) or otherprogrammable logic device, discrete gate or transistor logic, discretehardware components, or it may be a combination of these types ofcomponents. In such cases, the processor 120 may be an example of acentral processing unit (CPU), a graphics processing unit (GPU), ageneral purpose GPU (GPGPU), or a system on a chip (SoC), among otherexamples.

The BIOS component 125 may be a software component that includes a BIOSoperated as firmware, which may initialize and run various hardwarecomponents of the system 100. The BIOS component 125 may also managedata flow between the processor 120 and the various components of thesystem 100, e.g., the peripheral components 130, the I/O controller 135,etc. The BIOS component 125 may include a program or software stored inread-only memory (ROM), flash memory, or any other non-volatile memory.

The peripheral component(s) 130 may be any input device or outputdevice, or an interface for such devices, that may be integrated into orwith the system 100. Examples may include disk controllers, soundcontroller, graphics controller, Ethernet controller, modem, universalserial bus (USB) controller, a serial or parallel port, or peripheralcard slots, such as peripheral component interconnect (PCI) orspecialized graphics ports. The peripheral component(s) 130 may be othercomponents understood by those skilled in the art as peripherals.

The I/O controller 135 may manage data communication between theprocessor 120 and the peripheral component(s) 130, input devices 145, oroutput devices 150. The I/O controller 135 may manage peripherals thatare not integrated into or with the system 100. In some cases, the I/Ocontroller 135 may represent a physical connection or port to externalperipheral components.

The input 145 may represent a device or signal external to the system100 that provides information, signals, or data to the system 100 or itscomponents. This may include a user interface or interface with orbetween other devices. In some cases, the input 145 may be a peripheralthat interfaces with system 100 via one or more peripheral components130 or may be managed by the I/O controller 135.

The output 150 may represent a device or signal external to the system100 configured to receive an output from the system 100 or any of itscomponents. Examples of the output 150 may include a display, audiospeakers, a printing device, or another processor on printed circuitboard, and so forth. In some cases, the output 150 may be a peripheralthat interfaces with the system 100 via one or more peripheralcomponents 130 or may be managed by the I/O controller 135.

The components of system 100 may be made up of general-purpose orspecial purpose circuitry designed to carry out their functions. Thismay include various circuit elements, for example, conductive lines,transistors, capacitors, inductors, resistors, amplifiers, or otheractive or passive elements, configured to carry out the functionsdescribed herein.

The memory device 110 may include a device memory controller 155 and oneor more memory dice 160. Each memory die 160 may include a local memorycontroller 165 (e.g., local memory controller 165-a, local memorycontroller 165-b, and/or local memory controller 165-N) and a memoryarray 170 (e.g., memory array 170-a, memory array 170-b, and/or memoryarray 170-N). A memory array 170 may be a collection (e.g., a grid) ofmemory cells, with each memory cell being configured to store at leastone bit of digital data. Features of memory arrays 170 and/or memorycells are described in more detail with reference to FIG. 2 .

The memory device 110 may be an example of a two-dimensional (2D) arrayof memory cells or may be an example of a three-dimensional (3D) arrayof memory cells. For example, a 2D memory device may include a singlememory die 160. A 3D memory device may include two or more memory dice160 (e.g., memory die 160-a, memory die 160-b, and/or any quantity ofmemory dice 160-N). In a 3D memory device, a set of memory dice 160-Nmay be stacked on top of one another or next to one another. In somecases, memory dice 160-N in a 3D memory device may be referred to asdecks, levels, layers, or dies. A 3D memory device may include anyquantity of stacked memory dice 160-N (e.g., two high, three high, fourhigh, five high, six high, seven high, eight high). This may increasethe quantity of memory cells that may be positioned on a substrate ascompared with a single 2D memory device, which in turn may reduceproduction costs or increase the performance of the memory array, orboth. In some 3D memory devices, different decks may share at least onecommon access line such that some decks may share at least one of a wordline, a digit line, and/or a plate line.

The device memory controller 155 may include circuits or componentsconfigured to control operation of the memory device 110. As such, thedevice memory controller 155 may include the hardware, firmware, andsoftware that enables the memory device 110 to perform commands and maybe configured to receive, transmit, or execute commands, data, orcontrol information related to the memory device 110. The device memorycontroller 155 may be configured to communicate with the external memorycontroller 105, the one or more memory dice 160, or the processor 120.In some cases, the memory device 110 may receive data and/or commandsfrom the external memory controller 105. For example, the memory device110 may receive a write command indicating that the memory device 110 isto store certain data on behalf of a component of the system 100 (e.g.,the processor 120) or a read command indicating that the memory device110 is to provide certain data stored in a memory die 160 to a componentof the system 100 (e.g., the processor 120). In some cases, the devicememory controller 155 may control operation of the memory device 110described herein in conjunction with the local memory controller 165 ofthe memory die 160. Examples of the components included in the devicememory controller 155 and/or the local memory controllers 165 mayinclude receivers for demodulating signals received from the externalmemory controller 105, decoders for modulating and transmitting signalsto the external memory controller 105, logic, decoders, amplifiers,filters, or the like.

The local memory controller 165 (e.g., local to a memory die 160) may beconfigured to control operations of the memory die 160. Also, the localmemory controller 165 may be configured to communicate (e.g., receiveand transmit data and/or commands) with the device memory controller155. The local memory controller 165 may support the device memorycontroller 155 to control operation of the memory device 110 asdescribed herein. In some cases, the memory device 110 does not includethe device memory controller 155, and the local memory controller 165 orthe external memory controller 105 may perform the various functionsdescribed herein. As such, the local memory controller 165 may beconfigured to communicate with the device memory controller 155, withother local memory controllers 165, or directly with the external memorycontroller 105 or the processor 120.

The external memory controller 105 may be configured to enablecommunication of information, data, and/or commands between componentsof the system 100 (e.g., the processor 120) and the memory device 110.The external memory controller 105 may act as a liaison between thecomponents of the system 100 and the memory device 110 so that thecomponents of the system 100 may not need to know the details of thememory device's operation. The components of the system 100 may presentrequests to the external memory controller 105 (e.g., read commands orwrite commands) that the external memory controller 105 satisfies. Theexternal memory controller 105 may convert or translate communicationsexchanged between the components of the system 100 and the memory device110. In some cases, the external memory controller 105 may include asystem clock that generates a common (source) system clock signal. Insome cases, the external memory controller 105 may include a common dataclock that generates a common (source) data clock signal.

In some cases, the external memory controller 105 or other component ofthe system 100, or its functions described herein, may be implemented bythe processor 120. For example, the external memory controller 105 maybe hardware, firmware, or software, or some combination thereofimplemented by the processor 120 or other component of the system 100.While the external memory controller 105 is depicted as being externalto the memory device 110, in some cases, the external memory controller105, or its functions described herein, may be implemented by a memorydevice 110. For example, the external memory controller 105 may behardware, firmware, or software, or some combination thereof implementedby the device memory controller 155 or one or more local memorycontrollers 165. In some cases, the external memory controller 105 maybe distributed across the processor 120 and the memory device 110 suchthat portions of the external memory controller 105 are implemented bythe processor 120 and other portions are implemented by a device memorycontroller 155 or a local memory controller 165. Likewise, in somecases, one or more functions ascribed herein to the device memorycontroller 155 or local memory controller 165 may in some cases beperformed by the external memory controller 105 (either separate from oras included in the processor 120).

The components of the system 100 may exchange information with thememory device 110 using a set of channels 115. In some examples, thechannels 115 may enable communications between the external memorycontroller 105 and the memory device 110. Each channel 115 may includeone or more signal paths or transmission mediums (e.g., conductors)between terminals associated with the components of system 100. Forexample, a channel 115 may include a first terminal including one ormore pins or pads at external memory controller 105 and one or more pinsor pads at the memory device 110. A pin may be an example of aconductive input or output point of a device of the system 100, and apin may be configured to act as part of a channel.

In some cases, a pin or pad of a terminal may be part of to a signalpath of the channel 115. Additional signal paths may be coupled with aterminal of a channel for routing signals within a component of thesystem 100. For example, the memory device 110 may include signal paths(e.g., signal paths internal to the memory device 110 or its components,such as internal to a memory die 160) that route a signal from aterminal of a channel 115 to the various components of the memory device110 (e.g., a device memory controller 155, memory dice 160, local memorycontrollers 165, memory arrays 170).

Channels 115 (and associated signal paths and terminals) may bededicated to communicating specific types of information. In some cases,a channel 115 may be an aggregated channel and thus may include multipleindividual channels. For example, a data channel 190 may be x4 (e.g.,including four signal paths), x8 (e.g., including eight signal paths),x16 (including sixteen signal paths), and so forth. Signals communicatedover the channels may use double data rate (DDR) signaling. For example,some symbols of a signal may be registered on a rising edge of a clocksignal and other symbols of the signal may be registered on a fallingedge of the clock signal. Signals communicated over channels may usesingle data rate (SDR) signaling. For example, one symbol of the signalmay be registered for each clock cycle.

In some cases, the channels 115 may include one or more command andaddress (CA) channels 186. The CA channels 186 may be configured tocommunicate commands between the external memory controller 105 and thememory device 110 including control information associated with thecommands (e.g., address information). For example, the CA channel 186may include a read command with an address of the desired data. In somecases, the CA channels 186 may be registered on a rising clock signaledge and/or a falling clock signal edge. In some cases, a CA channel 186may include any quantity of signal paths to decode address and commanddata (e.g., eight or nine signal paths).

In some cases, the channels 115 may include one or more clock signal(CK) channels 188. The CK channels 188 may be configured to communicateone or more common clock signals between the external memory controller105 and the memory device 110. Each clock signal may be configured tooscillate between a high state and a low state and coordinate theactions of the external memory controller 105 and the memory device 110.

In some cases, the clock signal may be a differential output (e.g., aCK_t signal and a CK_c signal) and the signal paths of the CK channels188 may be configured accordingly. In some cases, the clock signal maybe single ended. A CK channel 188 may include any quantity of signalpaths. In some cases, the clock signal CK (e.g., a CK_t signal and aCK_c signal) may provide a timing reference for command and addressingoperations for the memory device 110, or other system-wide operationsfor the memory device 110. The clock signal CK therefore may bevariously referred to as a control clock signal CK, a command clocksignal CK, or a system clock signal CK. The system clock signal CK maybe generated by a system clock, which may include one or more hardwarecomponents (e.g., oscillators, crystals, logic gates, transistors, orthe like).

In some cases, the channels 115 may include one or more data (DQ)channels 190. The DQ channels 190 may be configured to communicate dataand/or control information between the external memory controller 105and the memory device 110. For example, the DQ channels 190 maycommunicate information (e.g., bi-directional) to be written to thememory device 110 or information read from the memory device 110.

In some cases, an indication of a state of error associated with data ofa read operation may be communicated using one or more of the channels115. That is, the memory device 110 may perform an in-line errorcorrection operation on data associated with a read operation. Theindicator of the state of error may indicate a status of an errorcorrection operation associated with the data. The indicator of thestate of error may be communicated over the one or more error indicatorchannels 192. In some cases, the error indicator channel 192 maycorrespond to a channel dedicated for the indication of the state oferror. In some other cases, the error indicator channel 192 maycorrespond to another channel. For example, the error indicator channel192 may be a data mask/invert (DMI) pin or a channel for impedancecalibration of the one or more DQ channels 190 (e.g., a ZQ channel).Additionally or alternatively, the memory device 110 may communicate theindicator of the state of error via the one or more DQ channels 190. Forexample, the memory device 110 may communicate the indicator of thestate of error by the DQ channels 190 after (e.g., contiguous with orseparated by one or more clock cycles) a burst interval forcommunicating the data associated with the read command to the externalmemory controller 105.

In some cases, the channels 115 may include one or more other channels194 that may be dedicated to other purposes. These other channels 194may include any quantity of signal paths.

In some cases, the other channels 194 may include one or more writeclock signal (WCK) channels. While the ‘W’ in WCK may nominally standfor “write,” a write clock signal WCK (e.g., a WCK_t signal and a WCK_csignal) may provide a timing reference for access operations generallyfor the memory device 110 (e.g., a timing reference for both read andwrite operations). Accordingly, the write clock signal WCK may also bereferred to as a data clock signal WCK. The WCK channels may beconfigured to communicate a common data clock signal between theexternal memory controller 105 and the memory device 110. The data clocksignal may be configured to coordinate an access operation (e.g., awrite operation or read operation) of the external memory controller 105and the memory device 110. In some cases, the write clock signal may bea differential output (e.g., a WCK_t signal and a WCK_c signal) and thesignal paths of the WCK channels may be configured accordingly. A WCKchannel may include any quantity of signal paths. The data clock signalWCK may be generated by a data clock, which may include one or morehardware components (e.g., oscillators, crystals, logic gates,transistors, or the like).

In some cases, the other channels 194 may include one or more errordetection code (EDC) channels. The EDC channels may be configured tocommunicate error detection signals, such as checksums, to improvesystem reliability. An EDC channel may include any quantity of signalpaths.

The channels 115 may couple the external memory controller 105 with thememory device 110 using a variety of different architectures. Examplesof the various architectures may include a bus, a point-to-pointconnection, a crossbar, a high-density interposer such as a siliconinterposer, or channels formed in an organic substrate or somecombination thereof. For example, in some cases, the signal paths may atleast partially include a high-density interposer, such as a siliconinterposer or a glass interposer.

Signals communicated over the channels 115 may be modulated using avariety of different modulation schemes. In some cases, a binary-symbol(or binary-level) modulation scheme may be used to modulate signalscommunicated between the external memory controller 105 and the memorydevice 110. A binary-symbol modulation scheme may be an example of aM-ary modulation scheme where M is equal to two. Each symbol of abinary-symbol modulation scheme may be configured to represent one bitof digital data (e.g., a symbol may represent a logic 1 or a logic 0).Examples of binary-symbol modulation schemes include, but are notlimited to, non-return-to-zero (NRZ), unipolar encoding, bipolarencoding, Manchester encoding, pulse amplitude modulation (PAM) havingtwo symbols (e.g., PAM2), and/or others.

In some cases, a multi-symbol (or multi-level) modulation scheme may beused to modulate signals communicated between the external memorycontroller 105 and the memory device 110. A multi-symbol modulationscheme may be an example of a M-ary modulation scheme where M is greaterthan or equal to three. Each symbol of a multi-symbol modulation schememay be configured to represent more than one bit of digital data (e.g.,a symbol may represent a logic 00, a logic 01, a logic 10, or a logic11). Examples of multi-symbol modulation schemes include, but are notlimited to, PAM4, PAM8, etc., quadrature amplitude modulation (QAM),quadrature phase shift keying (QPSK), and/or others. A multi-symbolsignal or a PAM4 signal may be a signal that is modulated using amodulation scheme that includes at least three levels to encode morethan one bit of information. Multi-symbol modulation schemes and symbolsmay alternatively be referred to as non-binary, multi-bit, orhigher-order modulation schemes and symbols.

The memory device 110 may be configured to perform an error correctionoperation on data read from a memory array 170 according to a readcommand (e.g., as received from the external memory controller 105). Theerror correction operation may generate corrected data and/or anindication of a detected error. The memory device 110 may output data(e.g., the corrected data or the data read from the memory array) to theexternal memory controller 105 during a burst interval. The memorydevice 110 may also output an indication of a status of the errorcorrection operation during the same burst interval. In one example, theindicator of the state of error may indicate one of three or morepossible states of error. In another example, the indicator of the stateof error may indicate that the error correction operation corrected anerror or did not detect an error.

FIG. 2 illustrates an example of a memory die 200 in accordance withexamples as disclosed herein. The memory die 200 may be an example ofthe memory dice 160 described with reference to FIG. 1 . In some cases,the memory die 200 may be referred to as a memory chip, a memory device,or an electronic memory apparatus. The memory die 200 may include one ormore memory cells 205 that are programmable to store different logicstates. Each memory cell 205 may be programmable to store two or morestates. For example, the memory cell 205 may be configured to store onebit of digital logic at a time (e.g., a logic 0 and a logic 1). In somecases, a single memory cell 205 (e.g., a multi-level memory cell) may beconfigured to store more than one bit of digit logic at a time (e.g., alogic 00, logic 01, logic 10, or a logic 11).

A memory cell 205 may store a charge representative of the programmablestates in a capacitor. DRAM architectures may include a capacitor thatincludes a dielectric material to store a charge representative of theprogrammable state. In other memory architectures, other storage devicesand components are possible. For example, nonlinear dielectric materialsmay be employed.

Operations such as reading and writing may be performed on memory cells205 by activating or selecting access lines such as a word line 210and/or a digit line 215. In some cases, digit lines 215 may also bereferred to as bit lines. References to access lines, word lines anddigit lines, or their analogues, are interchangeable without loss ofunderstanding or operation. Activating or selecting a word line 210 or adigit line 215 may include applying a voltage to the respective line.

The memory die 200 may include the access lines (e.g., the word lines210 and the digit lines 215) arranged in a grid-like pattern. Memorycells 205 may be positioned at intersections of the word lines 210 andthe digit lines 215. By biasing a word line 210 and a digit line 215(e.g., applying a voltage to the word line 210 or the digit line 215), asingle memory cell 205 may be accessed at their intersection.

Accessing the memory cells 205 may be controlled through a row decoder220 or a column decoder 225. For example, a row decoder 220 may receivea row address from the local memory controller 260 and activate a wordline 210 based on the received row address. A column decoder 225 mayreceive a column address from the local memory controller 260 and mayactivate a digit line 215 based on the received column address. Forexample, the memory die 200 may include multiple word lines 210, labeledWL_1 through WL_M, and multiple digit lines 215, labeled DL_1 throughDL_N, where M and N depend on the size of the memory array. Thus, byactivating a word line 210 and a digit line 215, e.g., WL_1 and DL_3,the memory cell 205 at their intersection may be accessed. Theintersection of a word line 210 and a digit line 215, in either atwo-dimensional or three-dimensional configuration, may be referred toas an address of a memory cell 205.

The memory cell 205 may include a logic storage component, such ascapacitor 230 and a switching component 235. The capacitor 230 may be anexample of a dielectric capacitor or a ferroelectric capacitor. A firstnode of the capacitor 230 may be coupled with the switching component235 and a second node of the capacitor 230 may be coupled with a voltagesource 240. In some cases, the voltage source 240 may be the cell platereference voltage, such as Vpl, or may be ground, such as Vss. In somecases, the voltage source 240 may be an example of a plate line coupledwith a plate line driver. The switching component 235 may be an exampleof a transistor or any other type of switch device that selectivelyestablishes or de-establishes electronic communication between twocomponents.

Selecting or deselecting the memory cell 205 may be accomplished byactivating or deactivating the switching component 235. The capacitor230 may be in electronic communication with the digit line 215 using theswitching component 235. For example, the capacitor 230 may be isolatedfrom digit line 215 when the switching component 235 is deactivated, andthe capacitor 230 may be coupled with digit line 215 when the switchingcomponent 235 is activated. In some cases, the switching component 235is a transistor and its operation may be controlled by applying avoltage to the transistor gate, where the voltage differential betweenthe transistor gate and transistor source may be greater or less than athreshold voltage of the transistor. In some cases, the switchingcomponent 235 may be a p-type transistor or an n-type transistor. Theword line 210 may be in electronic communication with the gate of theswitching component 235 and may activate/deactivate the switchingcomponent 235 based on a voltage being applied to word line 210.

A word line 210 may be a conductive line in electronic communicationwith a memory cell 205 that is used to perform access operations on thememory cell 205. In some architectures, the word line 210 may be inelectronic communication with a gate of a switching component 235 of amemory cell 205 and may be configured to control the switching component235 of the memory cell. In some architectures, the word line 210 may bein electronic communication with a node of the capacitor of the memorycell 205 and the memory cell 205 may not include a switching component.

A digit line 215 may be a conductive line that connects the memory cell205 with a sense component 245. In some architectures, the memory cell205 may be selectively coupled with the digit line 215 during portionsof an access operation. For example, the word line 210 and the switchingcomponent 235 of the memory cell 205 may be configured to couple and/orisolate the capacitor 230 of the memory cell 205 and the digit line 215.In some architectures, the memory cell 205 may be in electroniccommunication (e.g., constant) with the digit line 215.

The sense component 245 may be configured to detect a state (e.g., acharge) stored on the capacitor 230 of the memory cell 205 and determinea logic state of the memory cell 205 based on the stored state. Thecharge stored by a memory cell 205 may be extremely small, in somecases. As such, the sense component 245 may include one or more senseamplifiers to amplify the signal output by the memory cell 205. Thesense amplifiers may detect small changes in the charge of a digit line215 during a read operation and may produce signals corresponding to alogic state 0 or a logic state 1 based on the detected charge. During aread operation, the capacitor 230 of memory cell 205 may output a signal(e.g., discharge a charge) to its corresponding digit line 215. Thesignal may cause a voltage of the digit line 215 to change. The sensecomponent 245 may be configured to compare the signal received from thememory cell 205 across the digit line 215 to a reference signal 250(e.g., reference voltage). The sense component 245 may determine thestored state of the memory cell 205 based on the comparison. Forexample, in binary-signaling, if digit line 215 has a higher voltagethan the reference signal 250, the sense component 245 may determinethat the stored state of memory cell 205 is a logic 1 and, if the digitline 215 has a lower voltage than the reference signal 250, the sensecomponent 245 may determine that the stored state of the memory cell 205is a logic 0. The sense component 245 may include various transistors oramplifiers to detect and amplify a difference in the signals. Thedetected logic state of memory cell 205 may be output through ECC block265 by I/O 255. Here, the ECC block 265 may perform an error correctionoperation on the detected logic state of memory cell 205 and output data(e.g., the original data or corrected data) by I/O 255. In some othercases, the detected logic state of memory cell 205 may bypass ECC block265 and be output by I/O 255. In some cases, the detected logic state ofmemory cell 205 may be output through the ECC block 265 and around ECCblock 265 by I/O 255. Here, the detected logic state of memory cell 205may be output from the memory die 200 at a same time as ECC block 265performs an error correction operation on the detected logic state ofmemory cell 205. In some cases, the sense component 245 may be part ofanother component (e.g., a column decoder 225, row decoder 220). In somecases, the sense component 245 may be in electronic communication withthe row decoder 220 or the column decoder 225.

The local memory controller 260 may control the operation of memorycells 205 through the various components (e.g., row decoder 220, columndecoder 225, and sense component 245, ECC block 265). The local memorycontroller 260 may be an example of the local memory controller 165described with reference to FIG. 1 . In some cases, one or more of therow decoder 220, column decoder 225, sense component 245, and ECC block265 may be co-located with the local memory controller 260. The localmemory controller 260 may be configured to receive commands and/or datafrom an external memory controller 105 (or a device memory controller155 described with reference to FIG. 1 ), translate the commands and/ordata into information that can be used by the memory die 200, performone or more operations on the memory die 200, and communicate data fromthe memory die 200 to the external memory controller 105 (or the devicememory controller 155) in response to performing the one or moreoperations. The local memory controller 260 may generate row and columnaddress signals to activate the target word line 210 and the targetdigit line 215. The local memory controller 260 may also generate andcontrol various voltages or currents used during the operation of thememory die 200. In general, the amplitude, shape, or duration of anapplied voltage or current discussed herein may be adjusted or variedand may be different for the various operations discussed in operatingthe memory die 200.

In some cases, the local memory controller 260 may be configured toperform a write operation (e.g., a programming operation) on one or morememory cells 205 of the memory die 200. During a write operation, amemory cell 205 of the memory die 200 may be programmed to store adesired logic state. In some cases, a set of memory cells 205 may beprogrammed during a single write operation. The local memory controller260 may identify a target memory cell 205 on which to perform the writeoperation. The local memory controller 260 may identify a target wordline 210 and a target digit line 215 in electronic communication withthe target memory cell 205 (e.g., the address of the target memory cell205). The local memory controller 260 may activate the target word line210 and the target digit line 215 (e.g., applying a voltage to the wordline 210 or digit line 215), to access the target memory cell 205. Thelocal memory controller 260 may apply a specific signal (e.g., voltage)to the digit line 215 during the write operation to store a specificstate (e.g., charge) in the capacitor 230 of the memory cell 205, thespecific state (e.g., charge) may be indicative of a desired logicstate.

The ECC block 265 or the local memory controller 260 may perform one ormore error correction operations on data received from the host deviceas part of a write operation. For example, the ECC block 265 may receivedata from the host device as part of a write operation. The ECC block265 may determine or generate error detection or correction informationassociated with the data. In some cases, the ECC block 265 may includeerror detection logic or may cause error detection logic (not shown) toperform the error detection operations described herein. The ECC block265 may cause the data and the error detection or correction informationto be stored in one or more memory cells 205 as part of the writeoperation. In another example, the ECC block 265 may receive data andassociated error detection or correction information from a memory arrayas part of a read operation. The ECC block 265 may perform an errorcorrection operation based on the data and the error detection orcorrection information. Performing an error correction operation at thememory device (e.g., by the ECC block 265 or the local memory controller260) may improve the reliability of the memory device.

The ECC block 265 or the local memory controller 260 may generate anindicator of a status of the error correction operation. The indicatormay indicate a state of error of the data. For example, the indicatormay indicate a type of error correction or a type of error detectedduring the error correction operation. For example, the indicator of thestate of error may indicate one of three or more possible states oferror. In another example, the indicator of the state of error mayindicate that the error correction operation corrected an error or didnot detect an error.

In some cases, the local memory controller 260 may be configured toperform a read operation (e.g., a sense operation) on one or more memorycells 205 of the memory die 200. During a read operation, the logicstate stored in a memory cell 205 of the memory die 200 may bedetermined. In some cases, a set of memory cells 205 may be sensedduring a single read operation. The local memory controller 260 mayidentify a target memory cell 205 on which to perform the readoperation. The local memory controller 260 may identify a target wordline 210 and a target digit line 215 in electronic communication withthe target memory cell 205 (e.g., the address of the target memory cell205). The local memory controller 260 may activate the target word line210 and the target digit line 215 (e.g., applying a voltage to the wordline 210 or digit line 215), to access the target memory cell 205. Thetarget memory cell 205 may transfer a signal to the sense component 245in response to biasing the access lines. The sense component 245 mayamplify the signal. The local memory controller 260 may fire the sensecomponent 245 (e.g., latch the sense component) and thereby compare thesignal received from the memory cell 205 to the reference signal 250.Based on that comparison, the sense component 245 may determine a logicstate that is stored on the memory cell 205. The local memory controller260 may communicate the logic state stored on the memory cell 205 to theexternal memory controller 105 (or the device memory controller 155) aspart of the read operation.

As the logic state stored on the memory cell 205 is communicated betweena host device and a memory device, the data may be corrupted. The localmemory controller 260 or the ECC block 265 may generate an errorcorrecting code to be used to detect and/or correct some of theseerrors. Error correction used to detect or correct errors that occurduring the transmission of data over channels between the memory deviceand a host device or external memory controller may be referred to aslink ECC. The local memory controller 260 or the ECC block 265 maycommunicate the error correcting code to the external memory controller105 (e.g., in addition to the logic state stored on the memory cell 205)as part of the read operation. The local memory controller 260 or theECC block 265 may receive an error correcting code from the externalmemory controller 105 as part of a write operation and detect or correcterrors that occurred during transmission of the data associated with thewrite operation.

In some memory architectures, accessing the memory cell 205 may degradeor destroy the logic state stored in a memory cell 205. For example, aread operation performed in DRAM architectures may partially orcompletely discharge the capacitor of the target memory cell. The localmemory controller 260 may perform a re-write operation or a refreshoperation to return the memory cell to its original logic state. Thelocal memory controller 260 may re-write the logic state to the targetmemory cell after a read operation. In some cases, the re-writeoperation may be considered part of the read operation. Additionally,activating a single access line, such as a word line 210, may disturbthe state stored in some memory cells in electronic communication withthat access line. Thus, a re-write operation or refresh operation may beperformed on one or more memory cells that may not have been accessed.

FIG. 3 illustrates an example of a system 300 that supports a memorydevice with status feedback for error correction in accordance withexamples as disclosed herein. The system 300 may include one or morecomponents described herein with reference to FIGS. 1 and 2 , amongothers. For example, the system 300 may include a host device 305, whichmay be an example of the external memory controller 105 as describedwith reference to FIG. 1 ; a memory device 310, which may be an exampleof the memory device 110, the memory dice 160, or the memory die 200 asdescribed with reference to FIGS. 1 and 2 ; a controller 320, which maybe an example of the device memory controller 155, one or more localmemory controllers 165, or the local memory controller 260 as describedwith reference to FIGS. 1 and 2 , or any combination thereof; a memoryarray 325, which may be an example of the memory arrays 170 as describedwith reference to FIG. 1 ; an error correction circuit 330 which may bean example of the local memory controller 260 or the ECC block 265 asdescribed with reference to FIG. 2 ; and CA channels 386, CK channels388, DQ channels 390, and error indicator channels 392, which may beexamples of the corresponding channels as discussed with reference toFIG. 1 . The memory device 310 may also include a memory interface 315.

Host device 305 may send commands to memory device 310 by CA channel386, which may be received via the memory interface 315. The commandsmay include access commands to perform one or more access operations(e.g., a read operation, a write operation) at the memory array 325. Thecontroller 320 may receive commands from the memory interface 315,process the commands, and execute the commands on memory array 325. Theerror correction circuit 330 may perform one or more error correctionoperations on data associated with the access commands.

During a write operation, the host device 305 may send a write commandto the memory interface 315 by CA channel 386. The write command mayinclude data to be written to the memory array 325. The memory interface315 may send the data to the controller 320 which may in turncommunicate the data to the error correction circuit 330. The errorcorrection circuit 330 may generate error detection or correctioninformation based on the data received from controller 320. For example,the error correction circuit 330 may generate parity or Hamming codeinformation based on the data. The error correction circuit 330 maycommunicate the error detection or correction information to thecontroller 320 to be stored at the memory array 325 with the data. Thecontroller 320 may store the data at the memory array 325 (e.g., at alocation indicated by the write command received from the host device305). The controller 320 may also store the error detection orcorrection information at the memory array 325. In some cases, the errordetection or correction information may be stored at a same location asthe data (e.g., a same sub-array, a same row). In some other cases, theerror detection or correction information may be stored at a differentportion of the memory array 325 than the data.

During a read operation, the host device 305 may send a read command tothe memory interface 315 by CA channel 386. The read command mayindicate data to be read from the memory array 325. The memory interface315 may communicate the read command to the controller 320 which may inturn read the data (e.g., the first data) from the memory array 325. Thecontroller 320 may also read error detection or correction information(e.g., that is associated with the data) from the memory array 325. Thecontroller 320 may communicate both the data and the error detection orcorrection information to the error correction circuit 330. The errorcorrection circuit 330 may perform an error correction operation basedon the data to detect and/or correct errors associated with the data(e.g., due to leakage, parasitic coupling, or EMI). During the errorcorrection operation, the error correction circuit 330 may generateerror detection or correction information based on the data receivedfrom the controller 320. The error correction circuit 330 may comparethe received error detection or correction information with thegenerated error detection or correction information. In the event thatthe received error detection or correction information and the generatederror detection or correction information do not match, the errorcorrection circuit 330 may detect an error.

The error correction operation may detect and/or correct various typesof errors based on a type of the error correction operation. In a firstcase, the error correction operation may not detect any errors. In asecond case, the error correction operation may detect an error but notcorrect the error. For example, the error correction operation maydetect a double-bit error (e.g., during a SECDED operation), detect atriple-bit uncorrected error, detect an odd uncorrected error (e.g., anerror corresponding to an odd quantity of inverted bits within thedata), detect even uncorrected errors (e.g., an error corresponding toan even quantity of inverted bits within the data), or detect an aliasederror. In a third case, the error correction operation may correct anerror. For example, the error correction operation may correct asingle-bit error (e.g., during a single error correction (SEC) SEC orSEC double error detection (SECDED) operation), correct a triple-biterror, correct an odd error, or correct an even error.

Each of the types of error detection and/or correction may be classifiedinto a state of error. That is, there may be a finite possible states oferror and the error correction circuit 330 may determine, based on theerror correction operation, a state of error associated with the data.The quantity of possible states of errors and/or the possible states oferrors may be variable. In some cases, the states of errors may be apreconfigured characteristic of the memory device 310 (e.g., hardwiredon the memory device 310 or set during initialization). In some othercases, the states of errors may be programmable (e.g., by the hostdevice 305).

There may be two possible states of error. For example, the two statesof error may be (1) no error/undetectable error or (2) a correctederror. In a second example, the two possible states of error maycorrespond to (1) no error/undetectable error/corrected error or (2) analiased third error. In the first two examples, the error correctioncircuit 330 may determine the state of error (e.g., between the twopossible states of errors) based on performing an SEC operation. Thatis, the error correction circuit 330 may perform an SEC operation thatindicates whether there is (1) no error or an undetectable error (2) acorrected error or (3) an aliased error. The error correction circuit330 may categorize a subset or all of the types of errors into two errorcategories. For example, the two categories may be whether there is (1)no error or an undetectable error versus (2) a corrected error, orwhether there is (1) no error/undetectable error/corrected error versus(2) an aliased third error. In a third example, the two categories oferror may be (1) no error/correctable error or (2) an uncorrectableerror. In some cases, the error correction circuit 330 may not determinebetween (1) the no error/correctable error and (2) the uncorrectableerror based on an SEC error correction operation. In this case, the SECerror correction operation may not indicate an uncorrectable error. Theerror correction circuit 330 may output an indicator of the category oferror.

In some other cases, error correction circuit 330 may output anindicator that indicates one of more than two categories for states oferror. For example, there may be three possible states of errorcorresponding to (1) no error/undetectable error, (2) a corrected error,or (3) an uncorrected error. In a second example, there may be threepossible states of error corresponding to (1) no error detected, (2) acorrected error, or (3) an uncorrected error. Where additional errorinformation is available, for example for ECC more complex than SEC,there may be more than three possible states of error. For example, thepossible states of error may include (1) no error detected, (2) acorrecting single-bit error, (3) a detected double-bit error, (4) acorrected triple-bit error, (5) a detected triple-bit uncorrected error,(6) a corrected odd error, (7) a detected odd uncorrected error, (8) acorrected even error, or (9) a detected even uncorrected error. Theerror correction circuit 330 may categorize a subset or all of theerrors into two, or more (e.g., up to the total possible states oferror) error categories for generating the indicator of the error.

The error correction circuit 330 may output data (e.g., second data) tothe controller 320 based on the error correction operation. In somecases, the second data may be corrected data generated by performing theerror correction operation on the data read from the memory array 325.In some other cases, the second data may be the same as the data readfrom the memory array 325 (e.g., the error correction circuit 330 didnot correct any errors during the error correction operation). The errorcorrection circuit 330 may also communicate an indicator of the state oferror to the controller 320. Alternatively, the error correction circuit330 may communicate, to the controller 320, an indicator of the type orcategory of error detected and/or corrected during the error correctionoperation. Based on the type or category of error detected and/orcorrected, the controller 320 may determine the state of errorassociated with the data.

The controller 320 may communicate either the first data or the seconddata to the memory interface 315. The memory interface 315 may in turnoutput the data (e.g., the first data or the second data) to the hostdevice 305 by the DQ channel 390 according to a burst interval. Theburst interval may correspond to a quantity of clock cycles (e.g., basedon the WCK as discussed with reference to FIG. 1 ) to output the data bythe DQ channel 390 to the host device 305.

The controller 320 may communicate the indicator of the state of errorto the memory interface 315. The memory interface 315 may output theindicator of the state of error during the same burst interval (e.g., asthe data). In some cases, the memory interface 315 may communicate theindicator of the state of error by the DQ channel 390. Here, the memoryinterface 315 may serially output the indicator of the state of error toa backend of the data during the burst interval. In another case, thememory interface 315 may communicate the indicator of the state of errorby an error indicator channel 392. In some cases, the error indicatorchannel 392 may be dedicated for the indication of the state of error.Here, the memory interface 315 may be a flag. For example, the memoryinterface 315 may indicate one of two possible states of error bysetting the flag to one of two possible values.

Alternatively, the error indicator channel 392 may be a multi-functionalchannel. For example, the error indicator channel 392 may be a DMI pin.If the error indicator channel 392 is a DMI pin, the memory interface315 may output the indicator of the state of error during a firstportion of the burst interval. For example, the memory interface 315 mayoutput the indicator of the state of error during the first seven (7)clock cycles of a sixteen (16) cycle burst interval. Here, the seven (7)clock cycles may provide up to 2⁷ possible indications of the state oferror. In some cases, each clock cycle may correspond to a state oferror (e.g., each bit corresponds to a flag associated with a specificstate of error) to indicate a total of seven (7) different states oferror. In some other cases, there may be up to 2⁷ possible states oferror, where a combination of bits corresponds to a state of error. Inanother example, the error indicator channel 392 may be a ZQ channel(e.g., a channel associated with impedance calibration for the DQchannel 390) outside of ZQ calibration. The indicator of the state oferror may be coded (e.g., three (3) types or categories of error codedto four (4) or more bits).

Depending on a functionality of the error indicator channel 392, thememory interface 315 may utilize varying amounts of the burst intervalto output the indicator of the state of error (e.g., a first portion ofthe burst interval, a second portion of the burst interval, the entireburst interval). This may allow for a high possible degree ofgranularity of the possible states of errors. For example, if the burstinterval is sixteen (16) cycles and the entire burst interval isavailable for outputting the indicator of the state of error, the memoryinterface 315 may output a sixteen (16) bit indicator of the state oferror. Therefore, there may be up to 2¹⁶ possible states of errorindicated. Alternatively, there may be less than 2¹⁶ possible states oferror, but with a higher degree of redundancy (e.g., the indicator maybe transmitted more than one time or coded).

The error indicator channel 392 may include information in addition tothe indicator of the state of error. For example, the error indicatorchannel 392 may indicate information related to detected row hammerevents, refresh rate parameters for the memory device 310, or a mode ofoperation associated with the memory device 310. the mode of operationmay include an indication of whether the memory device 310 is operatingaccording to a safe mode. The safe mode may correspond to a restrictionof the operation of the memory device 310 (e.g., by limiting the type ofcommands executed, by limiting the portion of a memory array 325 of thememory device 310 for executing commands).

The memory interface 315 may output the indicator of the state of memoryto a mode register (e.g., that may be polled by the host device 305).The memory interface 315 may also store the second data at a moderegister for later retrieval. The memory interface 315 may store theindicator the state of memory at the mode register and output theindicator of the state of error by a channel to the host device 305.

By providing the memory device 310 with a method for communicatingmultiple different possible states of error, the system 300 may operatewith a higher reliability. Indicating a state of error with moregranularity (e.g., indicating a state of error from a larger quantity ofpossible states of error) may provide the host device 305 with moreinformation regarding the reliability of the data received from thememory device 310 during the read operation. This may further improvethe reliability of the memory system 300.

FIG. 4 illustrates an example of a timing diagram 400 that supports amemory device with status feedback for error correction in accordancewith examples as disclosed herein. The timing diagram 400 illustratesprocedures of read operation to output data stored at a memory array325. The timing diagram 400 shows various logical states (e.g., whichmay correspond to voltage levels as a function of time) associated withthe channels between a host device 305 and a memory device 310 asdescribed with reference to FIG. 3 . Thus, the timing diagram 400 mayillustrate the signal transmission on one or more channels describedherein with reference to FIGS. 1, 2, and 3 . Specifically, timingdiagram 400 may illustrate the signal transmissions on one or morechannels during a read operation when the memory device outputs anindicator of the state of error by an error indicator channel. The timeand voltage scales used in FIG. 4 are for illustration purposes only andmay not necessarily depict particular values in some cases. The timingdiagram 400 includes a CK channel 488, a CA channel 386, a WCK channel494, a DQ channel 490, and an error indicator channel 492, which may beexamples of the corresponding channels as discussed with reference toFIG. 1 and FIG. 3 .

At time 405, a memory device may receive a first read command from ahost device by the CA channel 486. The memory device may receive theread command at the transition of the signal on the CK channel 488. Attime 410, the memory device may receive a second read command from thehost device by the CA channel 486.

At time 415, the memory device may begin outputting, by the DQ channel490, data corresponding to the first read operation. The memory devicemay output the data according to the timing reference provided by theWCK channel 494. The time between time 405 and time 415 may correspondto a latency associated with the first read operation. The memory devicemay output the data corresponding to the read operation during a burstinterval from time 415 to time 425. Here, the burst interval maycorrespond to sixteen (16) cycles (e.g., as indicated by the signal onWCK channel 494). If the DQ channel 490 has a width of eight (8) (e.g.,includes eight (8) pins), the read operation may correspond to 128 bitsof data. In some cases, the DQ channel may have a width of sixteen (16).Here, the read operation may correspond to 256 bits of data.

During the burst interval from time 415 to time 425, the memory devicemay output an indicator of the state of error (e.g., corresponding tothe data on the DQ channel 490 from time 415 to time 425) to the hostdevice by the error indicator channel 492. The error indicator channel492 may be a multi-functional channel. In some cases, the errorindicator channel 492 may be a DMI pin. When the error indicator channel492 corresponds to a DMI pin, a portion of the burst interval (e.g.,from time 420 to time 425) may be used for other communications. Forexample, the last nine (9) bits on DMI pin may include link ECCinformation. That is, the memory device may perform an SEC or SECDEDoperation to generate error detection and correction information forlink ECC and output the error detection and correction informationwithin a last portion (e.g., the last nine (9) bits) of the burstinterval.

If the error indicator channel 492 is a DMI pin, the signal output bythe error indicator channel 492 from time 415 to time 420 may be anindicator the state of error. That is, a first portion (e.g., the firstseven (7) of the sixteen (16) bits) of the burst interval may indicatethe state of error while a second portion (e.g., the last nine (9) bitsindicates link ECC information. In some cases, each bit of the firstportion may be the same. Here, the indicator of the state of error mayindicate one of two possible states of error. In some other cases, theremay be less redundancy allowing for more possible states of error or theindicator to be output on a subset of the first portion of the burstinterval. In some cases, the state of error may be output in a differentportion of the bits of the burst interval (e.g., other than the firstportion of the burst interval).

For example, determining the state of error may involve more time thanis available prior to the burst interval and may not be output at thebeginning of the burst interval. Therefore, the state of error may beoutput in a last portion, or in bits that may be distributed throughoutthe burst interval (e.g., in-between the link ECC bits, in a combpattern). If the DQ channel has a width that satisfies a threshold(e.g., sixteen (16)), the error indicator channel 492 may include morethan one DMI pin, where each of the DMI pins corresponds to a distinctset (e.g., eight (8) pins) of the DQ channel 490. Therefore, the errorindicator channel 492 may indicate a state of error for half of the dataoutput by the DQ channel 490.

The error indicator channel 492 may be a different type of channel(e.g., a ZQ channel). Depending on a functionality of the errorindicator channel 492, the error indicator channel 492 may include avarying quantity of bits indicating the state of error. This may allowfor a high possible degree of granularity of the possible states oferrors. For example, if the entire burst interval is available foroutputting the indicator of the state of error, the entire signal on theerror indicator channel 492 from time 415 to time 425 may correspond toan indication of the state of error. Therefore, there may be up to 2^(N)possible states of error indicated, where N is the quantity of cycles inthe burst interval. Alternatively, there may be less than 2^(N) possiblestates of error, but with a higher degree of redundancy (e.g., theindicator may be transmitted more than one time or coded).

In some cases, the indicator of the state of error may be output by theDQ channel 490 instead of by the error indicator channel 492. Forexample, after the data for the read operation has been output by the DQchannel 490 at time 425, the DQ channel 490 may output an indicator ofthe state of error associated with the data. If the DQ channel 490includes eight (8) data pins, one or more of the data pins may output anindicator of the state of error in the clock cycle following time 425(e.g., the 17th clock cycle for a burst length of sixteen (16)).

If the indicator of the state of error is being output by the errorindicator channel 492, the memory device may begin outputting, by the DQchannel 490, data corresponding to the second read operation at time425. The time between 410 and 425 may correspond to a latency associatedwith the second read operation. The memory device may output the datacorresponding to the read operation during a burst interval from time425 to time 435. Again, the burst interval may correspond to sixteen(16) cycles (e.g., as indicated by the signal on WCK channel 494).During the burst interval from time 425 to time 435, the memory devicemay output an indicator of the state of error (e.g., corresponding tothe data on the DQ channel 490 from time 425 to time 435) to the hostdevice by the error indicator channel 492. If the error indicatorchannel 492 corresponds to a DMI pin, the indicator of the state oferror may be output during the first seven (7) cycles of the burstinterval from time 425 to time 430.

FIG. 5 illustrates an example of a process flow 500 that supports amemory device with status feedback for error correction in accordancewith examples as disclosed herein. The process flow 500 may implementaspects of the systems 100 and 300 and memory die 200 described withreference to FIGS. 1 through 3 . The process flow 500 may includeoperations performed by a host device 505, which may be an example ofhost device 305 as described with reference to FIG. 3 . Host device 505may implement aspects of the external memory controller 105 as describedwith reference to FIG. 1 . The process flow 500 may further includeoperations performed by a memory device 510, which may be an example ofthe memory device 110, the memory array 170, or the memory die 200, orthe memory device 310 as described with reference to FIGS. 1 through 3 .

At 515, the memory device 510 may receive a read command from hostdevice 505.

At 520, the memory device 510 may read first data of the memory arraybased on the read command.

At 525, the memory device 510 perform an error correction operation onthe first data to obtain second data and an indicator of a state oferror in the second data. In one example, the indicator of the state oferror may indicate one of at least three states of error. In one case,the at least three states of error may include no detectable error, acorrected error, or an aliased error. In another case, the at leastthree states of error may include no detectable error, a correctederror, or an uncorrected error. In a third case, the at least threestates of error include no detectable error, a corrected single-biterror, a detected double-bit error, a corrected triple-bit error, adetected triple-bit uncorrected error, a corrected odd error, a detectedodd uncorrected error, a corrected even error, or a detected evenuncorrected error.

In another example, the indicator of the state of error indicates acorrected error or no detectable error.

At 530, the memory device 510 may output data and the indicator of thestate of error to the host device 505 during a burst interval. The datamay be one of the first data or the second data. The memory device 510may output the data using a first channel of the memory device 510 andoutput the indicator of the state of error using the second channel ofthe memory device 510. In some cases, the first and second channel maybe different channels. For example, the first channel may be a datachannel. The second channel may be associated with impedance calibrationof the first channel. In some other cases, the first and second channelmay be the same channel. For example, the memory device 510 may outputthe indicator of the state of error serially with outputting the firstdata or the second data (e.g., by a same channel).

The burst interval (e.g., during which the memory device 510 outputs thedata and the indicator of the state of error) may include a set ofcycles. The memory device 510 may output the first data or the seconddata over the set of cycles using the first channel of the memory device510. The memory device 510 may output the indicator of the state oferror over a first portion of the set of cycles using the second channelof the memory device 510. The memory device 510 may output a link ECCover a second portion of the set of cycles using the second channel. Thesecond portion of the set of cycles may occur before the first portionof the set of cycles (e.g., the memory device 510 may output the linkECC before outputting the indicator of the state of error).

At 535, the memory device 510 may optionally store the indicator of thestate of error in a register at the memory device 510 based onperforming the error correction operation. In some cases, outputting theindicator of the state of error is based on storing the indicator of thestate of error in the register. The host device 505 may optionally pollthe register to receive the indicator of the state of error.

FIG. 6 shows a block diagram 600 of a memory device 605 that supports amemory device with status feedback for error correction in accordancewith examples as disclosed herein. The memory device 605 may be anexample of aspects of a memory device as described with reference toFIGS. 1, 3, and 5 . The memory device 605 may include a read commandreceiver 610, a data reading manager 615, an error correction component620, an output manager 625, and an indicator storage component 630. Eachof these modules may communicate, directly or indirectly, with oneanother (e.g., via one or more buses).

The read command receiver 610 may receive, at a memory device includinga memory array, a read command from a host device.

The data reading manager 615 may read first data of the memory arraybased on the read command.

The error correction component 620 may perform an error correctionoperation on the first data to obtain second data and an indicator of astate of error in the second data. In a first example, the indicator mayindicate one of at least three states of error. In some cases, the atleast three states of error include no detectable error, a correctederror, or an aliased error. In some other cases, the at least threestates of error include no detectable error, a corrected error, or anuncorrected error. In some other cases, the at least three states oferror include no detectable error, a corrected single-bit error, adetected double-bit error, a corrected triple-bit error, a detectedtriple-bit uncorrected error, a corrected odd error, a detected odduncorrected error, a corrected even error, or a detected evenuncorrected error. In a second example, the indicator may indicate acorrected error or no detectable error.

The output manager 625 may output, to the host device during a burstinterval, one of the first data or the second data using a first channelof the memory device and the indicator of the state of error using asecond channel of the memory device. In some cases, the second channelmay be different than the first channel. In some examples, the secondchannel is associated with impedance calibration of the first channel.In some cases, the output manager 625 may output a link error correctioncode using the second channel before outputting the indicator of theerror. In some examples, the output manager 625 outputs the indicator ofthe state of error serially with outputting the first data or the seconddata.

The burst interval may include a plurality of cycles. Here, the outputmanager 625 may output the first data or the second data over the set ofcycles using the first channel of the memory device. The output manager625 may further output the indicator of the state of error over a firstportion of the set of cycles using the second channel of the memorydevice different than the first channel. In some examples, the outputmanager 625 outputs a link error correction code over a second portionof the set of cycles using the second channel. In some cases, the secondportion of the set of cycles occurs before the first portion of the setof cycles.

The indicator storage component 630 may store the indicator of the stateof error in a register at the memory device based on performing theerror correction operation. In some examples, the indicator storagecomponent 630 stores the indicator of the state of error in a registerduring the burst interval, where outputting the indicator of the stateof error is based on storing the indicator of the state of error in theregister.

FIG. 7 shows a flowchart illustrating a method or methods 700 thatsupports a memory device with status feedback for error correction inaccordance with examples of the present disclosure. The operations ofmethod 700 may be implemented by a memory device or its components asdescribed herein. For example, the operations of method 700 may beperformed by a memory device as described with reference to FIG. 6 . Insome examples, a memory device executes a set of instructions to controlthe functional elements of the memory device to perform the describedfunctions. Additionally or alternatively, a memory device may performaspects of the described functions using special-purpose hardware.

At 705, the memory device including a memory array may receive a readcommand from a host device. The operations of 705 may be performedaccording to the methods described herein. In some examples, aspects ofthe operations of 705 may be performed by a read command receiver asdescribed with reference to FIG. 6 .

At 710, the memory device may read first data of the memory array basedon the read command. The operations of 710 may be performed according tothe methods described herein. In some examples, aspects of theoperations of 710 may be performed by a data reading manager asdescribed with reference to FIG. 6 .

At 715, the memory device may perform an error correction operation onthe first data to obtain second data and an indicator of a state oferror in the second data. The operations of 715 may be performedaccording to the methods described herein. In some examples, aspects ofthe operations of 715 may be performed by an error correction componentas described with reference to FIG. 6 .

At 720, the memory device may output, to the host device during a burstinterval, one of the first data or the second data using a first channelof the memory device and the indicator of the state of error using asecond channel of the memory device different than the first channel,where the indicator indicates one of at least three states of error. Theoperations of 720 may be performed according to the methods describedherein. In some examples, aspects of the operations of 720 may beperformed by an output manager as described with reference to FIG. 6 .

In some examples, an apparatus as described herein may perform a methodor methods, such as the method 700. The apparatus may include features,means, or instructions (e.g., a non-transitory computer-readable mediumstoring instructions executable by a processor) for receiving, at amemory device including a memory array, a read command from a hostdevice, reading first data of the memory array based on the readcommand, performing an error correction operation on the first data toobtain second data and an indicator of a state of error in the seconddata, and outputting, to the host device during a burst interval, one ofthe first data or the second data using a first channel of the memorydevice and the indicator of the state of error using a second channel ofthe memory device different than the first channel, where the indicatorindicates one of at least three states of error.

In some examples of the method 700 and the apparatus described herein,the burst interval may include operations, features, means, orinstructions for outputting the first data or the second data over theset of cycles using the first channel of the memory device, andoutputting the indicator of the state of error over a first portion ofthe set of cycles using the second channel of the memory devicedifferent than the first channel.

Some examples of the method 700 and the apparatus described herein mayfurther include operations, features, means, or instructions foroutputting a link error correction code over a second portion of the setof cycles using the second channel.

In some cases of the method 700 and the apparatus described herein, thesecond portion of the set of cycles occurs before the first portion ofthe set of cycles.

In some instances of the method 700 and the apparatus described herein,the second channel may be associated with impedance calibration of thefirst channel.

Some examples of the method 700 and the apparatus described herein mayfurther include operations, features, means, or instructions foroutputting the indicator of the state of error serially with outputtingthe first data or the second data.

Some cases of the method 700 and the apparatus described herein mayfurther include operations, features, means, or instructions for storingthe indicator of the state of error in a register at the memory devicebased on performing the error correction operation.

In some instances of the method 700 and the apparatus described herein,the at least three states of error include no detectable error, acorrected error, or an aliased error.

In some examples of the method 700 and the apparatus described herein,the at least three states of error include no detectable error, acorrected error, or an uncorrected error.

In some cases of the method 700 and the apparatus described herein, theat least three states of error include no detectable error, a correctedsingle-bit error, a detected double-bit error, a corrected triple-biterror, a detected triple-bit uncorrected error, a corrected odd error, adetected odd uncorrected error, a corrected even error, or a detectedeven uncorrected error.

FIG. 8 shows a flowchart illustrating a method or methods 800 thatsupports a memory device with status feedback for error correction inaccordance with examples of the present disclosure. The operations ofmethod 800 may be implemented by a memory device or its components asdescribed herein. For example, the operations of method 800 may beperformed by a memory device as described with reference to FIG. 6 . Insome examples, a memory device may execute a set of instructions tocontrol the functional elements of the memory device to perform thedescribed functions. Additionally or alternatively, a memory device mayperform aspects of the described functions using special-purposehardware.

At 805, the memory device may receive, at a memory device including amemory array, a read command from a host device. The operations of 805may be performed according to the methods described herein. In someexamples, aspects of the operations of 805 may be performed by a readcommand receiver as described with reference to FIG. 6 .

At 810, the memory device may read first data of the memory array basedon the read command. The operations of 810 may be performed according tothe methods described herein. In some examples, aspects of theoperations of 810 may be performed by a data reading manager asdescribed with reference to FIG. 6 .

At 815, the memory device may perform an error correction operation onthe first data to obtain second data and an indicator of a state oferror in the second data. The operations of 815 may be performedaccording to the methods described herein. In some examples, aspects ofthe operations of 815 may be performed by an error correction componentas described with reference to FIG. 6 .

At 820 and 825, the memory device may output, to the host device duringa burst interval, one of the first data or the second data using a firstchannel of the memory device and the indicator of the state of errorusing a second channel of the memory device different than the firstchannel, where the indicator indicates one of at least three states oferror.

At 820, the memory device may output the first data or the second dataover the set of cycles using the first channel of the memory device. Theoperations of 820 may be performed according to the methods describedherein. In some examples, aspects of the operations of 820 may beperformed by an output manager as described with reference to FIG. 6 .

At 825, the memory device may output the indicator of the state of errorover a first portion of the set of cycles using the second channel ofthe memory device different than the first channel. The operations of825 may be performed according to the methods described herein. In someexamples, aspects of the operations of 825 may be performed by an outputmanager as described with reference to FIG. 6 .

FIG. 9 shows a flowchart illustrating a method or methods 900 thatsupports a memory device with status feedback for error correction inaccordance with examples of the present disclosure. The operations ofmethod 900 may be implemented by a memory device or its components asdescribed herein. For example, the operations of method 900 may beperformed by a memory device as described with reference to FIG. 6 . Insome examples, a memory device may execute a set of instructions tocontrol the functional elements of the memory device to perform thedescribed functions. Additionally or alternatively, a memory device mayperform aspects of the described functions using special-purposehardware.

At 905, the memory device may receive, at a memory device including amemory array, a read command from a host device. The operations of 905may be performed according to the methods described herein. In someexamples, aspects of the operations of 905 may be performed by a readcommand receiver as described with reference to FIG. 6 .

At 910, the memory device may read first data of the memory array basedon the read command. The operations of 910 may be performed according tothe methods described herein. In some examples, aspects of theoperations of 910 may be performed by a data reading manager asdescribed with reference to FIG. 6 .

At 915, the memory device may perform an error correction operation onthe first data to obtain second data and an indicator of a state oferror in the second data, where the indicator indicates a correctederror or no detectable error. The operations of 915 may be performedaccording to the methods described herein. In some examples, aspects ofthe operations of 915 may be performed by an error correction componentas described with reference to FIG. 6 .

At 920, the memory device may output, to the host device during a burstinterval, one of the first data or the second data using a first channeland the indicator of the state of error using a second channel. Theoperations of 920 may be performed according to the methods describedherein. In some examples, aspects of the operations of 920 may beperformed by an output manager as described with reference to FIG. 6 .

In some examples, an apparatus as described herein may perform a methodor methods, such as the method 900. The apparatus may include features,means, or instructions (e.g., a non-transitory computer-readable mediumstoring instructions executable by a processor) for receiving, at amemory device including a memory array, a read command from a hostdevice, reading first data of the memory array based on the readcommand, performing an error correction operation on the first data toobtain second data and an indicator of a state of error in the seconddata, where the indicator indicates a corrected error or no detectableerror, and outputting, to the host device during a burst interval, oneof the first data or the second data using a first channel and theindicator of the state of error using a second channel.

Some examples of the method 900 and the apparatus described herein mayfurther include operations, features, means, or instructions foroutputting a link error correction code using the second channel beforeoutputting the indicator of the error.

In some cases of the method 900 and the apparatus described herein, thesecond channel may be associated with impedance calibration of the firstchannel.

Some instances of the method 900 and the apparatus described herein mayfurther include operations, features, means, or instructions foroutputting, using a channel, the indicator of the state of errorserially with outputting the first data or the second data.

Some examples of the method 900 and the apparatus described herein mayfurther include operations, features, means, or instructions for storingthe indicator of the state of error in a register during the burstinterval, where outputting the indicator of the state of error may bebased on storing the indicator of the state of error in the register.

It should be noted that the methods described above describe possibleimplementations, and that the operations and the steps may be rearrangedor otherwise modified and that other implementations are possible.Furthermore, aspects from two or more of the methods may be combined.

In some examples, an apparatus corresponding to a memory device withstatus feedback for error correction may perform aspects of the functiondescribed herein using general- or special-purpose hardware. Theapparatus may include an array of memory cells that each includecapacitive storage elements, an interface configured to receive a readcommand from a host device, a first circuit coupled with the interfaceand the array of memory cells and configured to read first data from thearray of memory cells based on the read command, and a second circuitcoupled to the first circuit and configured to perform an errorcorrection operation on the first data to obtain second data and anindicator of a state of error in the second data, where the indicator ofthe state of error indicates one of at least three states of error. Theinterface may be configured to communicate, with the host device, theindicator of the state of error and one of the first data or the seconddata during a burst interval.

In some examples, the burst interval includes a set of cycles and theinterface is configured to output the first data or the second data overthe set of cycles via a first channel, and output the indicator of thestate of error over a first portion of the set of cycles via a secondchannel different than the first channel.

In some cases, the second channel is further configured to communicate alink error correction code over a second portion of the set of cycles.

In some instances, the second portion of the set of cycles occurs beforethe first portion of the set of cycles.

In some examples, the interface is further configured to communicate theindicator of the state of error via a first channel serially withcommunicating the first data or the second data via the first channel.

In some cases, the at least three states of error include no detectableerror, a corrected error, or an aliased error. In some other cases, theat least three states of error include no detectable error, a correctederror, or an uncorrected error. In some other cases, the at least threestates of error comprise no detectable error, a corrected single-biterror, a detected double-bit error, a corrected triple-bit error, adetected triple-bit uncorrected error, a corrected odd error, a detectedodd uncorrected error, a corrected even error, or a detected evenuncorrected error.

Information and signals described herein may be represented using any ofa variety of different technologies and techniques. For example, data,instructions, commands, information, signals, bits, symbols, and chipsthat may be referenced throughout the above description may berepresented by voltages, currents, electromagnetic waves, magneticfields or particles, optical fields or particles, or any combinationthereof. Some drawings may illustrate signals as a single signal;however, it will be understood by a person of ordinary skill in the artthat the signal may represent a bus of signals, where the bus may have avariety of bit widths.

As used herein, the term “virtual ground” refers to a node of anelectrical circuit that is held at a voltage of approximately zero volts(0V) but that is not directly coupled with ground. Accordingly, thevoltage of a virtual ground may temporarily fluctuate and return toapproximately 0V at steady state. A virtual ground may be implementedusing various electronic circuit elements, such as a voltage dividerconsisting of operational amplifiers and resistors. Otherimplementations are also possible. “Virtual grounding” or “virtuallygrounded” means connected to approximately 0V.

The terms “electronic communication,” “conductive contact,” “connected,”and “coupled” may refer to a relationship between components thatsupports the flow of signals between the components. Components areconsidered in electronic communication with (or in conductive contactwith or connected with or coupled with) one another if there is anyconductive path between the components that can, at any time, supportthe flow of signals between the components. At any given time, theconductive path between components that are in electronic communicationwith each other (or in conductive contact with or connected with orcoupled with) may be an open circuit or a closed circuit based on theoperation of the device that includes the connected components. Theconductive path between connected components may be a direct conductivepath between the components or the conductive path between connectedcomponents may be an indirect conductive path that may includeintermediate components, such as switches, transistors, or othercomponents. In some cases, the flow of signals between the connectedcomponents may be interrupted for a time, for example, using one or moreintermediate components such as switches or transistors.

The term “coupling” refers to condition of moving from an open-circuitrelationship between components in which signals are not presentlycapable of being communicated between the components over a conductivepath to a closed-circuit relationship between components in whichsignals are capable of being communicated between components over theconductive path. When a component, such as a controller, couples othercomponents together, the component initiates a change that allowssignals to flow between the other components over a conductive path thatpreviously did not permit signals to flow.

The term “isolated” refers to a relationship between components in whichsignals are not presently capable of flowing between the components.Components are isolated from each other if there is an open circuitbetween them. For example, two components separated by a switch that ispositioned between the components are isolated from each other when theswitch is open. When a controller isolates two components, thecontroller affects a change that prevents signals from flowing betweenthe components using a conductive path that previously permitted signalsto flow.

The devices discussed herein, including a memory array, may be formed ona semiconductor substrate, such as silicon, germanium, silicon-germaniumalloy, gallium arsenide, gallium nitride, etc. In some cases, thesubstrate is a semiconductor wafer. In other cases, the substrate may bea silicon-on-insulator (SOI) substrate, such as silicon-on-glass (SOG)or silicon-on-sapphire (SOP), or epitaxial layers of semiconductormaterials on another substrate. The conductivity of the substrate, orsub-regions of the substrate, may be controlled through doping usingvarious chemical species including, but not limited to, phosphorous,boron, or arsenic. Doping may be performed during the initial formationor growth of the substrate, by ion-implantation, or by any other dopingmeans.

A switching component or a transistor discussed herein may represent afield-effect transistor (FET) and comprise a three terminal deviceincluding a source, drain, and gate. The terminals may be connected toother electronic elements through conductive materials, e.g., metals.The source and drain may be conductive and may comprise a heavily-doped,e.g., degenerate, semiconductor region. The source and drain may beseparated by a lightly-doped semiconductor region or channel. If thechannel is n-type (i.e., majority carriers are signals), then the FETmay be referred to as a n-type FET. If the channel is p-type (i.e.,majority carriers are holes), then the FET may be referred to as ap-type FET. The channel may be capped by an insulating gate oxide. Thechannel conductivity may be controlled by applying a voltage to thegate. For example, applying a positive voltage or negative voltage to ann-type FET or a p-type FET, respectively, may result in the channelbecoming conductive. A transistor may be “on” or “activated” when avoltage greater than or equal to the transistor's threshold voltage isapplied to the transistor gate. The transistor may be “off” or“deactivated” when a voltage less than the transistor's thresholdvoltage is applied to the transistor gate.

The description set forth herein, in connection with the appendeddrawings, describes example configurations and does not represent allthe examples that may be implemented or that are within the scope of theclaims. The term “exemplary” used herein means “serving as an example,instance, or illustration,” and not “preferred” or “advantageous overother examples.” The detailed description includes specific details toproviding an understanding of the described techniques. Thesetechniques, however, may be practiced without these specific details. Insome instances, well-known structures and devices are shown in blockdiagram form to avoid obscuring the concepts of the described examples.

In the appended figures, similar components or features may have thesame reference label. Further, various components of the same type maybe distinguished by following the reference label by a dash and a secondlabel that distinguishes among the similar components. If just the firstreference label is used in the specification, the description isapplicable to any one of the similar components having the same firstreference label irrespective of the second reference label.

Information and signals described herein may be represented using any ofa variety of different technologies and techniques. For example, data,instructions, commands, information, signals, bits, symbols, and chipsthat may be referenced throughout the above description may berepresented by voltages, currents, electromagnetic waves, magneticfields or particles, optical fields or particles, or any combinationthereof.

The various illustrative blocks and modules described in connection withthe disclosure herein may be implemented or performed with ageneral-purpose processor, a DSP, an ASIC, an FPGA or other programmablelogic device, discrete gate or transistor logic, discrete hardwarecomponents, or any combination thereof designed to perform the functionsdescribed herein. A general-purpose processor may be a microprocessor,but in the alternative, the processor may be any processor, controller,microcontroller, or state machine. A processor may also be implementedas a combination of computing devices (e.g., a combination of a DSP anda microprocessor, multiple microprocessors, one or more microprocessorsin conjunction with a DSP core, or any other such configuration).

The functions described herein may be implemented in hardware, softwareexecuted by a processor, firmware, or any combination thereof. Ifimplemented in software executed by a processor, the functions may bestored on or transmitted over as one or more instructions or code on acomputer-readable medium. Other examples and implementations are withinthe scope of the disclosure and appended claims. For example, due to thenature of software, functions described above can be implemented usingsoftware executed by a processor, hardware, firmware, hardwiring, orcombinations of any of these. Features implementing functions may alsobe physically located at various positions, including being distributedsuch that portions of functions are implemented at different physicallocations. Also, as used herein, including in the claims, “or” as usedin a list of items (for example, a list of items prefaced by a phrasesuch as “at least one of” or “one or more of”) indicates an inclusivelist such that, for example, a list of at least one of A, B, or C meansA or B or C or AB or AC or BC or ABC (i.e., A and B and C). Also, asused herein, the phrase “based on” shall not be construed as a referenceto a closed set of conditions. For example, an exemplary step that isdescribed as “based on condition A” may be based on both a condition Aand a condition B without departing from the scope of the presentdisclosure. In other words, as used herein, the phrase “based on” shallbe construed in the same manner as the phrase “based at least in parton.”

Computer-readable media includes both non-transitory computer storagemedia and communication media including any medium that facilitatestransfer of a computer program from one place to another. Anon-transitory storage medium may be any available medium that can beaccessed by a general purpose or special purpose computer. By way ofexample, and not limitation, non-transitory computer-readable media cancomprise RAM, ROM, electrically erasable programmable read-only memory(EEPROM), compact disk (CD) ROM or other optical disk storage, magneticdisk storage or other magnetic storage devices, or any othernon-transitory medium that can be used to carry or store desired programcode means in the form of instructions or data structures and that canbe accessed by a general-purpose or special-purpose computer, or ageneral-purpose or special-purpose processor. Also, any connection isproperly termed a computer-readable medium. For example, if the softwareis transmitted from a website, server, or other remote source using acoaxial cable, fiber optic cable, twisted pair, digital subscriber line(DSL), or wireless technologies such as infrared, radio, and microwave,then the coaxial cable, fiber optic cable, twisted pair, digitalsubscriber line (DSL), or wireless technologies such as infrared, radio,and microwave are included in the definition of medium. Disk and disc,as used herein, include CD, laser disc, optical disc, digital versatiledisc (DVD), floppy disk and Blu-ray disc where disks usually reproducedata magnetically, while discs reproduce data optically with lasers.Combinations of the above are also included within the scope ofcomputer-readable media.

The description herein is provided to enable a person skilled in the artto make or use the disclosure. Various modifications to the disclosurewill be apparent to those skilled in the art, and the generic principlesdefined herein may be applied to other variations without departing fromthe scope of the disclosure. Thus, the disclosure is not limited to theexamples and designs described herein, but is to be accorded thebroadest scope consistent with the principles and novel featuresdisclosed herein.

What is claimed is:
 1. An apparatus, comprising: an array of memorycells; and a controller coupled with the array of memory cells, a firstchannel, and a second channel, wherein the controller is configured tocause the apparatus to: receive a read command from a host device; readfirst data of the array of memory cells based at least in part on theread command; perform an error correction operation on the first data toobtain second data and an indicator of a state of error in the seconddata; and output, to the host device during a burst interval, one of thefirst data or the second data using the first channel and the indicatorof the state of error using the second channel, wherein the indicatorindicates one of at least three states of error.
 2. The apparatus ofclaim 1, wherein the burst interval comprises a plurality of cycles, thecontroller further configured to cause the apparatus to: output thefirst data or the second data over the plurality of cycles using thefirst channel; and output the indicator of the state of error over afirst portion of the plurality of cycles using the second channel. 3.The apparatus of claim 2, wherein the controller is further configuredto cause the apparatus to: output a link error correction code over asecond portion of the plurality of cycles using the second channel. 4.The apparatus of claim 3, wherein the second portion of the plurality ofcycles occurs before the first portion of the plurality of cycles. 5.The apparatus of claim 2, wherein the second channel is associated withimpedance calibration of the first channel.
 6. The apparatus of claim 1,wherein the controller is further configured to cause the apparatus to:output the indicator of the state of error serially with outputting thefirst data or the second data.
 7. The apparatus of claim 1, wherein thecontroller is further configured to cause the apparatus to: store theindicator of the state of error in a register based at least in part onperforming the error correction operation.
 8. The apparatus of claim 1,wherein the at least three states of error comprise no detectable error,a corrected error, or an aliased error.
 9. The apparatus of claim 1,wherein the at least three states of error comprise no detectable error,a corrected error, or an uncorrected error.
 10. The apparatus of claim1, wherein the at least three states of error comprise no detectableerror, a corrected single-bit error, a detected double-bit error, acorrected triple-bit error, a detected triple-bit uncorrected error, acorrected odd error, a detected odd uncorrected error, a corrected evenerror, or a detected even uncorrected error.
 11. An apparatus,comprising: an array of memory cells; and a controller coupled with thearray of memory cells, a first channel, and a second channel, whereinthe controller is configured to cause the apparatus to: receive a readcommand from a host device; read a first data of the array of memorycells based at least in part on the read command; perform an errorcorrection operation on the first data to obtain second data and a stateof error in the second data; output, to the host device during a burstinterval, one of the first data or the second data using the firstchannel; and output, using the second channel, a first indicator duringa first portion of the burst interval and a second indicator during asecond portion of the burst interval, wherein the first indicatorindicates the state of error.
 12. The apparatus of claim 11, wherein thefirst channel comprises a plurality of data pins and the second channelcomprises one or more data mask/invert pins.
 13. The apparatus of claim12, wherein the controller is further configured to cause the apparatusto: output the second indicator using the second channel beforeoutputting the first indicator indicating the state of error based atleast in part on the second channel comprising the one or more datamask/invert pins, wherein the second indicator comprises a link errorcorrection code.
 14. The apparatus of claim 12, wherein the secondchannel comprises multiple data mask/invert pins based at least in parton a width of the first channel satisfying a threshold.
 15. Theapparatus of claim 11, wherein the first channel comprises a datachannel and the second channel comprises an impedance calibrationchannel associated with the first channel.
 16. The apparatus of claim15, wherein the controller is further configured to cause the apparatusto: output a quantity of bits comprising the state of error, wherein thequantity of bits is based at least in part on a quantity of clock cyclesin the first portion of the burst interval.
 17. The apparatus of claim11, wherein the first channel and the second channel are a same channel.18. The apparatus of claim 17, wherein the controller is furtherconfigured to cause the apparatus to: output the first indicatorindicating the state of error serially with outputting the first data orthe second data based at least in part on the first channel and thesecond channel being the same channel.
 19. The apparatus of claim 11,wherein the controller is further configured to cause the apparatus to:store the first indicator in a register during the burst interval,wherein outputting the first indicator is based at least in part onstoring the first indicator in the register.
 20. A method, comprising:receiving, at a memory device comprising a memory array, a read commandfrom a host device; reading first data of the memory array based atleast in part on the read command; performing an error correctionoperation on the first data to obtain second data and a state of errorin the second data; outputting, to the host device during a burstinterval, one of the first data or the second data using a firstchannel; and outputting, using a second channel, a first indicatorduring a first portion of the burst interval and a second indicatorduring a second portion of the burst interval, wherein the firstindicator indicates the state of error.